Valentine's Day is coming up, the second busiest mailing day of the year. You take it for granted that our valentines will get to their destinations within a few days . . . thanks to air mail. A new book by local author Kathleen Wunderly documents the key role played by the central Pennsylvania town of Bellefonte when the U.S. Postal Service first launched "Aerial Mail Service" in 1918-back in the days of Curtis Jenny biplanes!